Contact Lens Video Display Electronics Now Transparent

Transparent and stretchable electrodes made of graphene and silver nanowires that are effective conductors have been developed by researchers at South Korea’s Ulsan National Institute of Science and Technology (UNIST).

The scientists were able to embed the new material as an inorganic light-emitting diode (ILDED) into a soft contact lens which was worn seemingly without irritation by a live rabbit for five hours.

Transparent electrodes that can remain electrically conductive and stable under large mechanical deformations are highly desirable for applications in flexible and wearable electronics. This paper describes a comprehensive study of the electrical, optical, and mechanical properties of hybrid nanostructures based on two-dimensional graphene and networks of one-dimensional metal nanowires, and their use as transparent and stretchable electrodes. Low sheet resistance (33 Ω/sq) with high transmittance (94% in visible range), robust stability against electric breakdown and oxidation, and superb flexibility (27% in bending strain) and stretchability (100% in tensile strain) are observed, and these multiple functionalities of the hybrid structures suggest a future promise for next generation electronics.

The use of hybrid electrodes to fabricate oxide semiconductor transistors and single-pixel displays integrated on wearable soft contact lenses with in vivo tests are demonstrated.